Political parties use different media during the electoral campaign period to send out their messages and appeal for popular support. Although the role and importance of web-based social media has dramatically increased in recent years, in most countries traditional media, such as radio, TV and print media are still the most widely used during the campaign period.

State-owned media favouritism towards incumbent candidates and parties—in terms of biased reporting, gender discrimination in coverage and reporting, coverage time, discrimination against opposition forces, unethical reporting and so on—is often a factor in raising tensions. Private media may adopt the same practices to champion their own favoured candidates. Such a scenario can increase tensions and fuel election-related violence directed against both political opponents and critical and/or investigative journalists. 

Empirical cases: 

• Cambodia parliamentary election 2008. Most media networks were perceived as biased towards the Cambodia People’s Party (CPP) during the elections. In addition, a journalist working for Moneaksekar Khmer, an opposition newspaper affiliated with the Sam Rainsy Party (SRP), was killed roughly two weeks before election day. The journalist was well known for his critical articles on official corruption. The fact that no one was arrested for the murders was interpreted by observers as a warning signal to other journalists and opposition members.[1]
  
  Interrelated factors: problematic voter registration (internal); poor voter information campaign (internal);[2] problematic election day operations (internal); poor management of the final round of electoral appeals (internal); the presence of non-state armed actors (external); poor voter information campaign (internal); poor management of election results (internal).[3]